


Colliding on a Backdrop of Blue

by StormyDaze



Category: Captain America (Movies)
Genre: 69 (Sex Position), Anal Sex, Belly Kink, MPREG SEX, Mpreg, Multi, Oral Sex, Sex Pollen, Sex Pollen Orgy, Vaginal Fingering
Language: English
Status: Completed
Published: 2019-07-25
Updated: 2019-07-25
Packaged: 2020-07-19 06:18:32
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,000
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19969411
Author URL: https://archiveofourown.org/users/StormyDaze/pseuds/StormyDaze
Summary: On a mission, Sam, Steve, Natasha, and Bucky come in contact with a mysterious blue liquid.





	Colliding on a Backdrop of Blue

**Author's Note:**

  * For [lionessvalenti](https://archiveofourown.org/users/lionessvalenti/gifts).



> I was already idly contemplating writing a treat for you, so when I saw your pinch hit, I snapped it up! "Natasha, Steve, Sam, and Bucky go on missions and also fuck" is one of my favorite types of MCU fic. Let's call this canon divergent after CA:TWS, shall we?
> 
> Title from "Blue Lips" by Regina Spektor.

“I knew I shouldn’t have let you come,” Steve mumbled under his breath.

“You don’t _let_ me do anything,” Bucky said mildly, but there was a spark in his eye that Sam didn’t like. Bucky rested his metal hand on the gentle swell of his belly. They weren’t sure, exactly, how far along he was, but he’d already been showing when they’d found him three months ago. It didn’t seem to slow him down any. Privately, Sam would have preferred Bucky stay home as well, but Bucky and Steve fought enough about it that Sam decided he wasn’t getting involved. 

They’d fought about it again before this mission, Steve getting louder and louder while Bucky got softer but no less menacing. In the end, it was Natasha who shut it down. “Don’t take any more choices away from him,” she said to Steve, and that was that, and Bucky was suiting up with the rest of them, although Steve’s lips were still pinched and white.

Of course, then the… whatever it was AIM was fucking around with exploded, showering them all with some kind of blue fluid that quickly evaporated into mist, and Steve hadn’t stopped fussing over Bucky since. Natasha flew the Quinjet, and Steve fussed and Bucky glowered and Sam tried to make himself as inconspicuous as possible. 

It was warm on the jet, and Sam fidgeted in his seat. A restless energy thrummed through him. He was anxious about whatever chemical they’d been doused with and eager to get back to the safe house and have SHIELD check them out, although there didn’t seem to be any effects so far. His uniform seemed tight and constricting, and he desperately wanted to get back to his room and take it off. And maybe take a cold shower, that seemed like a good idea.

Natasha had barely landed the jet on the safe house’s landing strip (Bucky argued that a safe house where you could land a jet wasn’t very secret, but Sam insisted that it was both safe and a house and therefore still deserved the name) before Steve was helping Bucky up, one arm draped protectively around his shoulders as he led him down the jet’s stairs. Sam expected Bucky to shove him off, but instead he leaned into the touch. In fact, was he… nuzzling Steve’s neck?

Sam’s face flushed. Anyone with two brain cells could see that Steve and Bucky were head over heels for each other, and it really would be easier on Sam’s heart if they’d just take the plunge already. The fact that he couldn’t tell who he was more jealous of was also a problem. He was a grown-ass man who could deal with his grown-ass feelings himself, but that didn’t mean he had to watch while they flirted ineptly like teenagers.

Sam turned away and almost jumped out of his skin when he saw Natasha standing about three inches from him. The woman was like a goddamn cat, always sneaking around, but usually she was more into personal space than this. 

Something was wrong. Her cheeks were red, and her pupils were wide black pits that swallowed her irises. Sam opened his mouth to ask her if she was feeling okay, and then she threw her arms around his neck and kissed him.

Every neuron in his brain short-circuited. Sure, he’d been pining after Steve and Bucky for a while now, but he’d never _dared_ to pine after Natasha. Even thinking about her while he jerked off in the shower felt too dangerous, like she’d see the thoughts in his head and come after his balls with a stiletto. 

So for a single moment, shock and pleasure overrode all his senses, and he let himself drown in that perfect kiss. 

Then his sense of self-preservation kicked in, and he jerked back, nearly tumbling down the stairs out of the jet. He caught himself and skittered down onto solid ground. Natasha followed much more gracefully.

“Are you… feeling all right?” Sam asked her. His lips tingled from that kiss. There wasn’t a cell in his body that didn’t hate the fact that he had to take being kissed by the most beautiful woman on earth as a sign of something going horribly wrong, but that was his life these days.

“Sam,” Natasha breathed, wrapping her arms around him again. She ground her hips against his thigh. “I need…”

“Some cold water, and possibly medical attention?” Sam offered. “Let’s… let’s just get you inside, okay?” His phone was in his pocket, but he couldn’t reach it with Natasha on top of him like this. He’d take her inside, get her to lie down, and then call Fury. Or have Steve do it, if Natasha wouldn’t give him the chance.

Natasha rubbed up against him again, a slow, sensual undulation of her hips, and Sam realized how very hard he was already. He gritted his teeth and tried to focus on anything except the warmth of her body against him, but it was like trying to ignore a wildfire as it consumed you. He ached to press back, to bury his face in that soft hair, to kiss his way up the pale arch of her neck.

Natasha wasn’t herself. And when she came back to herself, she was going to murder him. Slowly.

Sam managed to maneuver them inside, but they only made it as far as the front hallway, where Steve had Bucky up against the wall, Bucky’s shirt and tac vest mysteriously missing. Steve sucked gently on one of Bucky’s nipples, his eyes closed in apparent ecstasy.

Okay, so perhaps this was a larger problem than Sam had previously assumed.

AIM’s weird liquid/mist. It must have been some kind of drug. Sam wasn’t sure why he wasn’t affected, except that perhaps it was interfering with the supersoldier serum in some way. Natasha didn’t like to talk about her past, but she’d hinted at enough that he’d been able to connect some dots.

And really, now that he thought about it, he wasn’t entirely sure he _wasn’t_ affected, with how incredibly tight his pants felt around his hard cock right now. Although he’d challenge anyone to have Natasha wrapped around them like this and not be turned on, honestly.

Steve’s eyes opened, and he popped his mouth off Bucky’s nipple to beam at Sam. He reached out one enormous arm and tugged Sam close, bringing Natasha along for the ride. Steve cupped Sam’s face in those big hands and laid a series of clumsy kisses across his mouth, his jaw, his nose. 

When Steve relinquished his face, Sam saw Natasha nibbling at Bucky’s neck while Bucky had her catsuit unzipped to her crotch and his hand down her pants. He could feel Steve’s cock against his hip, already making a damp spot on his suit, and without thinking he slid his hands up the muscular planes of Steve’s back.

So he had three horny supersoldiers on his hands. He should stop this. He was pretty sure they would stop if he said so, if he meant it, and he tried to form the words, but what actually came out was, “Bed.”

Steve slid an arm under Sam’s ass and hoisted him up, and Sam wrapped his legs around Steve’s waist. From the noises behind him, it sounded like Natasha and Bucky were following, but Sam was too busy kissing behind Steve’s ear to pay too much attention. Steve had a small freckle right there, hidden behind his ear, which Sam found incredibly charming. He licked it, and then when Steve moaned, he licked it again. Steve’s free hand peeled the suit from Sam’s shoulders and glided over his back, and Sam ground against his waist.

The world shifted, and Sam found himself on his back on Steve’s bed. He scrabbled to kick off the rest of the constricting suit, and his briefs with it. Bucky landed next to him, and Sam was momentarily struck dumb by how beautiful he was. He’d always thought that thing about pregnancy glow was made up, but Bucky did seem to be glowing, and his round, taut belly was just begging to be touched. Sam slid a hand over it, gently, and Bucky arched into it. He caressed it gently with his hands and bent down to trace his tongue over soft pink stretch marks. To one side of him, Natasha, now minus her catsuit, tugged off Bucky’s pants and took his cock into her mouth, curling her lips over the head and then swallowing him down. Steve was back to sucking on one of Bucky’s nipples, rolling the other one gently between his fingers, and Bucky writhed underneath them as Sam continued to worship his belly. He could feel the moment when Bucky came, felt him tense and shudder, but he made surprisingly little noise, just a small whimper quickly stifled.

Bucky sat up, gasping, and Sam pulled away. Steve, standing beside the bed on Bucky’s other side, had finished undressing at some point, and now his cock stood up perfectly at Sam’s eye level. It was smaller than Sam would have guessed for someone Steve’s size, barely a handful really, but it was cute, and Sam let out a delighted giggle. He grabbed Steve’s hips and licked the head of his cock, and Steve wrapped his hands around the back of Sam’s head but didn’t pull or push, just held on as Sam licked and mouthed at the head. He flattened his tongue against the underside and then licked up, finishing by tonguing at the slit while Steve groaned, and then he wrapped his lips around it and took the whole thing. His nose brushed against Steve’s pubic hair just as the head of Steve’s cock hit the back of his throat, but that was fine. He laved the underside with his tongue, slowly bobbing back and forth. Steve tasted warm and musky. Sam sucked salty precome from the head before resuming his pace. The angle was awkward and it made Sam’s neck ache, but he wouldn’t trade anything in the world for the chance to have Steve’s perfect little cock in his mouth.

Steve came with a shout, spurting come down Sam’s throat, and he hurried to swallow it before it could dribble out of his mouth. Steve pulled him off and then bent down and kissed his own come from Sam’s lips, shoved him backwards onto the bed again and pinned him there with his body. Someone had found lube somewhere, and Steve slicked up a hand without taking his mouth off Sam’s. Steve slid one finger into his own hole, then two, fucking himself open as he rocked against Sam. Sam would have taken his time, would have liked to slowly break Steve open and watch him come apart around his fingers, but Steve was frenzied and reckless. He spread himself wide and then slid down onto Sam’s cock and oh, he was hot and tight and Sam nearly came right then and there, which would be a damn shame when he had so much left to see and touch and taste. Steve began to bounce up and down, fucking himself on Sam’s cock, and Sam did his best to match the thrust of his hips with Steve’s rhythm, but neither of them were capable of precise movements. Sam turned his head and saw Natasha and Bucky 69’ing, Bucky on his back licking at Natasha’s cunt like his life depended on it and Natasha on top of him, arms braced against the bed to keep too much of her weight off of Bucky’s round belly as her head bobbed up and down on his cock. Sam had a fraction of second to admire supersoldier refractory periods before Steve did something with his hips and Sam arched into him and came. Ecstasy coursed through his body and for a moment he ceased to exist as anything other than light and warmth and pleasure. He rocked his hips in time with the aftershocks of his orgasm and realized, by the cooling wetness on his chest, that Steve had come as well. He gently pushed Steve off, post-orgasmic oversensitivity setting in, and crawled up to the pile of pillows at the head of the bed to watch the rest of the show.

Natasha, her mouth smeared with Bucky’s come, lay down beside him, looking blissed out. On the other side of the bed, Steve and Bucky were going for round… three? Sam was losing count. This time, Bucky was on his hands and knees, belly hanging round and low beneath him, and Steve knelt on the bed behind him, pounding into him with quick snaps of his hips. Sam hadn’t seen him prep Bucky, but maybe he didn’t need much prep, with that little cock. Not that Bucky seemed to be complaining; quite the opposite in fact. His arms gave out and he collapsed face first into the bed, but he continued to thrust his ass back against Steve. Natasha reached over and lazily stroked Bucky’s cock, barely moving her hand but letting Bucky fuck into her fist as Steve increased the pace of his frantic thrusts. Bucky whined and whimpered, turning his face into the bed to muffle the noises, and Sam wondered if he could convince Bucky that he didn’t have to stifle himself. Maybe next time.

Not that there was going to be a next time. This was just some chemical side effect, nothing more, and trying to pretend otherwise would only end in heartbreak. To distract himself from that depressing train of thought, Sam dragged a hand down Natasha’s collarbone and down to cup her breast. Sam was sure he had never seen a more perfect breast in his life. He kneaded it gently with his fingers, enjoying the feeling of impossibly soft skin, and Natasha’s eyes closed and her mouth dropped open just a little. He bent his head down and licked her nipple, grazed it with his teeth, and then began to suck on it as he slid his hand across her flat stomach to the small, neatly trimmed patch of hair between her legs. She was dripping wet, and it was easy for Sam to slide two fingers inside her, fucking her slowly and deliberately with them now that the initial haze of urgency had somewhat worn off. He sucked and worried her nipple in his mouth while he fingered her sopping cunt, until she came hard around him, clenching down on his fingers as she rocked through her orgasm.

After that, things got fuzzy. Sam felt himself slipping slowly into sleep, as Steve, Bucky, and Natasha kept going. But he didn’t feel like he was missing out on anything, didn’t feel alone or left out. Instead, he rather thought that they liked having him watch, were maybe showing off for him, even though he didn’t have supersoldier stamina. He sank down into warm darkness, feeling content.

When he next opened his eyes, it was morning. He could tell by the angle of the clear light filtering through Steve’s blue curtains. Bucky was mostly on top of him, which Sam supposed was sort of necessary for the four of them to fit into the same bed, but his arm was starting to feel numb. He thought about it and decided against waking up a sleeping supersoldier.

Steve was awake too. His blue eyes met Sam’s own. Sam’s tongue flicked out to wet his parched lips. “How are you feeling?” he whispered, not wanting to wake Bucky or Natasha, whose red hair was splayed out across Steve’s chest.

“Thirsty,” Steve said. “But I don’t think I’ll be getting up for a glass of water any time soon.” He gave the top of Natasha’s head a fond smile.

“I meant, you know,” Sam said. “Are you… back to normal? Any weird side effects?” They never did get around to calling SHIELD. They should probably do that. Sam had no idea where his phone was. Probably wherever his suit ended up.

“I feel fine.” Steve’s brow creased as he frowned. “What about you? Are you okay? I’m so sorry Sam, I shouldn’t have—”

“I didn’t do anything I didn’t want to,” Sam said. “It was good.” His breath caught in his chest. “Really good.”

“This wasn’t how I expected this conversation to go,” Steve said.

“What conversation?”

“The one where we tell you we're in love with you,” Bucky said from somewhere around Sam’s armpit.

“Um,” Sam said. “I thought the two of you—”

“Well, duh.” Bucky poked his head up. His hair was a tangled mess that covered half his face. “That’s why he wanted to approach you all carefully. Thought you might get spooked.”

“For what it’s worth, I said you could handle it,” Natasha said without opening her eyes.

“Were all of you conspiring to, um, seduce me?” Sam asked. His voice went embarrassingly high on that last bit.

“Bucky needed some extra time too,” Natasha said.

“Which is why we were supposed to, you know, talk about it,” Steve said. “Like mature, responsible adults.”

Sam thought about that for a moment. “I think this was more fun,” he said at last. Bucky made a grunt into the side of his neck that sounded like agreement.

“Less talking, more sleeping,” Natasha said. Sam closed his eyes and drifted off again.

(Post credits scene)

Director Fury stood in the doorway, looking down at four very naked sleeping superheroes. Quite frankly, this was more of any of them than he’d ever wanted to see.

He’d been worried when they hadn’t checked in after the last mission. The jet had a tracker, which showed they’d landed at the safe house, but when he still hadn’t heard from them by morning, he’d come to check on them himself.

They appeared to be fine. In fact, he’d guess they’d enjoyed themselves quite a bit.

He shook his head and walked away.


End file.
